U.S. patent application number 12/502782 was filed with the patent office on 2010-01-21 for quantum dot solar cell.
This patent application is currently assigned to HONEYWELL INTERNATIONAL INC.. Invention is credited to Mircea Bercu, Cazimir-Gabriel Bostan, Stephan-Dan Costea, Viorel-Georgel Dumitru, Mihai N. Mihaila, Bogdan-Catalin Serban.
Application Number | 20100012191 12/502782 |
Document ID | / |
Family ID | 41529226 |
Filed Date | 2010-01-21 |
United States Patent
Application |
20100012191 |
Kind Code |
A1 |
Serban; Bogdan-Catalin ; et
al. |
January 21, 2010 |
QUANTUM DOT SOLAR CELL
Abstract
Example solar cells and methods for making and using the same
are disclosed. An example solar cell may include an electron
conductor layer, a quantum dot layer, a bifunctional ligand layer
coupling the electron conductor layer and the quantum dot layer,
and a hole conductor layer coupled to the quantum dot layer. The
bifunctional ligand layer may include an antibiotic, and in some
cases, a cephalosporin-based antibiotic.
Inventors: |
Serban; Bogdan-Catalin;
(Bucharest, RO) ; Mihaila; Mihai N.; (Bucharest,
RO) ; Dumitru; Viorel-Georgel; (Prahova, RO) ;
Bostan; Cazimir-Gabriel; (Bucharest, RO) ; Costea;
Stephan-Dan; (Bucharest, RO) ; Bercu; Mircea;
(Bucharest, RO) |
Correspondence
Address: |
HONEYWELL INTERNATIONAL INC.;PATENT SERVICES
101 COLUMBIA ROAD, P O BOX 2245
MORRISTOWN
NJ
07962-2245
US
|
Assignee: |
HONEYWELL INTERNATIONAL
INC.
Morristown
NJ
|
Family ID: |
41529226 |
Appl. No.: |
12/502782 |
Filed: |
July 14, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61080949 |
Jul 15, 2008 |
|
|
|
Current U.S.
Class: |
136/263 ;
136/252; 977/774 |
Current CPC
Class: |
H01L 51/424 20130101;
Y02E 10/549 20130101; H01L 51/4226 20130101; H01L 51/426
20130101 |
Class at
Publication: |
136/263 ;
136/252; 977/774 |
International
Class: |
H01L 31/0256 20060101
H01L031/0256; H01L 31/02 20060101 H01L031/02 |
Claims
1. A solar cell, comprising: an electron conductor layer; a quantum
dot layer; a bifunctional ligand layer coupling the electron
conductor layer and the quantum dot layer, the bifunctional ligand
layer including an antibiotic; and a hole conductor layer coupled
to the quantum dot layer.
2. The solar cell of claim 1, wherein the electron conductor layer
comprises titanium dioxide.
3. The solar cell of claim 1, wherein the bifunctional ligand layer
includes a cephalosporin-based antibiotic.
4. The solar cell of claim 1, wherein the bifunctional ligand layer
comprises one or more of ##STR00030## where R.sub.1 and R.sub.2
respectively are ##STR00031## where R.sub.1 and R.sub.2
respectively are ##STR00032##
5. The solar cell of claim 1, wherein the bifunctional ligand layer
comprises one or more of ##STR00033## where R.sub.1 and R.sub.2
respectively are ##STR00034## where R.sub.1 and R.sub.2
respectively are ##STR00035## where R.sub.1 is a chloride ion and
R.sub.2 is ##STR00036##
6. The solar cell of claim 1, wherein the bifunctional ligand layer
comprises one or more of ##STR00037## where R.sub.1 and R.sub.2
respectively are ##STR00038## where R.sub.1 is methyl and R.sub.2
is ##STR00039## where R.sub.1 and R.sub.2 respectively are
##STR00040##
7. The solar cell of claim 1, wherein the bifunctional ligand layer
comprises one or more of ##STR00041## where R.sub.1 and R.sub.2
respectively are ##STR00042## where R.sub.1 and R.sub.2
respectively are ##STR00043## where R.sub.1 and R.sub.2
respectively are ##STR00044##
8. The solar cell of claim 1, wherein the bifunctional ligand layer
comprises one or more of ##STR00045## where R.sub.1 is methyl and
R.sub.2 is ##STR00046## where R.sub.1 and R.sub.2 respectively are
##STR00047## where R.sub.1 and R.sub.2 respectively are:
##STR00048##
9. The solar cell of claim 1, wherein the bifunctional ligand layer
comprises one or more of ##STR00049## where R.sub.1 and R.sub.2
respectively are ##STR00050## where R.sub.1 and R.sub.2
respectively are ##STR00051## where R.sub.1 and R.sub.2
respectively are ##STR00052##
10. The solar cell of claim 1, wherein the bifunctional ligand
layer comprises one or more of ##STR00053## where R.sub.1 and
R.sub.2 respectively are ##STR00054## where R.sub.1 is methyl and
R.sub.2 is ##STR00055## where R.sub.1 and R.sub.2 respectively are
##STR00056##
11. The solar cell of claim 1, wherein the bifunctional ligand
layer comprises one or more of ##STR00057## where R.sub.1 and
R.sub.2 respectively are ##STR00058## where R.sub.1 and R.sub.2
respectively are ##STR00059## where R.sub.1 and R.sub.2
respectively are ##STR00060##
12. The solar cell of claim 1, wherein the hole conductor layer
comprises a conductive polymer that includes ##STR00061## as a
repeating unit.
13. The solar cell of claim 1, wherein the hole conductor layer
comprises a conductive polymer that includes ##STR00062## as a
repeating unit, where R is absent or alkyl.
14. The solar cell of claim 1, wherein the hole conductor layer
comprises a conductive polymer that includes ##STR00063## as a
repeating unit, where R is absent or alkyl and m is an integer
ranging from about 6 to about 12.
15. A solar cell, comprising: an electron conductor layer
comprising titanium dioxide; a plurality of quantum dots; a
plurality of bifunctional ligands, at least some of the plurality
of bifunctional ligands comprising an electron conductor anchor
that bonds to the electron conductor layer and a quantum dot anchor
that bonds to one of the plurality of quantum dots, at least some
of the plurality of bifunctional ligands comprising an antibiotic;
and a hole conductor layer comprising a conductive polymer
including a plurality of monomers, at least some of the plurality
of monomers being functionalized with a second quantum dot
anchor.
16. The solar cell of claim 15, wherein at least some of the
plurality of bifunctional ligands include a cephalosporin-based
antibiotic.
17. The solar cell of claim 15, wherein the hole conductor layer
includes: ##STR00064## as a repeating unit; ##STR00065## as a
repeating unit, where R is absent or alkyl; or ##STR00066## as a
repeating unit, where R is absent or alkyl and m is an integer
ranging from about 6 to about 12.
18. A solar cell, comprising: an electron conductor; one or more
quantum dots; a bifunctional ligand coupling the electron conductor
and the one or more quantum dots, the bifunctional ligand including
a cephalosporin-based ligand; and a hole conductor coupled to the
one or more quantum dots.
19. The solar cell of claim 18, wherein the electron conductor
comprises titanium dioxide.
20. The solar cell of claim 18, wherein the hole conductor includes
a conductive polymer.
Description
PRIORITY
[0001] This application claims priority under 35 U.S.C. .sctn.119
to U.S. Provisional Application Ser. No. 61/080,949 entitled
"QUANTUM DOT SOLAR CELL" filed Jul. 15, 2008, the entirety of which
is incorporated herein by reference.
TECHNICAL FIELD
[0002] The disclosure relates generally to solar cells, and more
particularly to quantum dot solar cells.
SUMMARY
[0003] The disclosure pertains generally to solar cells. In some
instances, a solar cell may include quantum dots as light
sensitizers.
[0004] An example solar cell may include an electron conductor
layer, a quantum dot layer, a bifunctional ligand layer coupling
the electron conductor layer and the quantum dot layer, and a hole
conductor layer coupled to the quantum dot layer. The bifunctional
ligand layer may include an antibiotic, and in some cases, a
cephalosporin-based antibiotic.
[0005] Another example solar cell may include an electron conductor
layer comprising titanium dioxide, a plurality of quantum dots, a
plurality of bifunctional ligands, and a hole conductor layer
comprising a conductive polymer including a plurality of monomers.
At least some of the plurality of bifunctional ligands may include
an electron conductor anchor that bonds to the electron conductor
layer and a quantum dot anchor that bonds to one of the plurality
of quantum dots. At least some of the plurality of bifunctional
ligands may include an antibiotic. At least some of the plurality
of monomers may be functionalized with a second quantum dot
anchor.
[0006] The above summary is not intended to describe each disclosed
embodiment or every implementation of the disclosure. The
Description which follows more particularly exemplifies various
examples.
BRIEF DESCRIPTION OF THE FIGURES
[0007] The following description should be read with reference to
the drawings. The drawings, which are not necessarily to scale,
depict selected embodiments and are not intended to limit the scope
of the disclosure. The disclosure may be more completely understood
in consideration of the following detailed description of various
embodiments in connection with the accompanying drawings, in
which:
[0008] FIG. 1 is a schematic cross-sectional side view of an
illustrative but non-limiting example of a solar cell; and
[0009] FIG. 2 is a schematic cross-sectional side view of another
illustrative but non-limiting example of a solar cell.
[0010] While the invention is amenable to various modifications and
alternative forms, specifics thereof have been shown by way of
example in the drawings and will be described in detail. It should
be understood, however, that the intention is not to limit the
invention to the particular embodiments or examples described. On
the contrary, the intention is to cover all modifications,
equivalents, and alternatives falling within the spirit and scope
of the invention.
DESCRIPTION
[0011] The following description should be read with reference to
the drawings, in which like elements in different drawings are
numbered in like fashion. The drawings, which are not necessarily
to scale, depict selected embodiments and are not intended to limit
the scope of the invention. Although examples of construction,
dimensions, and materials are illustrated for the various elements,
those skilled in the art will recognize that many of the examples
provided have suitable alternatives that may be utilized.
[0012] The term "alkyl" refers to a straight or branched chain
monovalent hydrocarbon radical having a specified number of carbon
atoms. Examples of "alkyl" include, but are not limited to, methyl,
ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl, n-pentyl,
n-hexyl, 3-methylpentyl, and the like.
[0013] FIG. 1 is a schematic cross-sectional side view of an
illustrative solar cell 10. In the illustrative example shown in
FIG. 1, there may be a three-dimensional intermingling or
interpenetration of the layers forming solar cell 10, but this is
not required. The illustrative solar cell 10 includes a quantum dot
layer 12. Quantum dot layer 12 may schematically represent a single
quantum dot. In some cases, quantum dot layer 12 may be considered
as representing a large number of individual quantum dots.
[0014] In the illustrative embodiment of FIG. 1, a bifunctional
ligand layer 14 is provided, and may schematically represent a
single bifunctional ligand, such as those discussed below. In some
cases, bifunctional ligand layer 14 may represent a large number of
individual bifunctional ligands, with at least some of the
bifunctional ligands within bifunctional ligand layer 14 bonded to
corresponding quantum dots within quantum dot layer 12. The
illustrative solar cell 10 of FIG. 1 also includes an electron
conductor layer 16. In some cases, electron conductor layer 16 may
be an n-type conductor as further discussed below. The illustrative
solar cell 10 may further include a hole conductor layer 18. As
discussed further below, hole conductor layer 18 may be a p-type
conducting electrode layer.
[0015] Bifunctional ligand layer 14 may, in some instances, be
considered as being coupled to quantum dot layer 12 as well as
being coupled to electron conductor layer 16. At least some of the
bifunctional ligands within bifunctional ligand layer 14 may be
considered as including electron conductor anchors that may bond to
electron conductor layer 12, and quantum dot anchors that may bond
to individual quantum dots within quantum dot layer 16. Hole
conductor layer 18 may also be considered as being coupled to
quantum dot layer 12. In some cases, two layers may be considered
as being coupled if one or more molecules or other moieties within
one layer are bonded or otherwise secured to one or more molecules
within another layer. In some instances, coupling infers the
potential passage of electrons from one layer to the next.
[0016] Quantum dot layer 12 may include one quantum dot or a
plurality of quantum dots. Quantum dots are typically very small
semiconductors, having dimensions in the nanometer range. Because
of their small size, quantum dots may exhibit quantum behavior that
is distinct from what would otherwise be expected from a larger
sample of the material. In some cases, quantum dots may be
considered as being crystals composed of materials from Groups
II-VI, III-V, or IV-VI materials. The quantum dots employed herein
may be formed using any appropriate technique. Examples of specific
pairs of materials for forming quantum dots include, but are not
limited to, MgO, MgS, MgSe, MgTe, CaO, CaS, CaSe, CaTe, SrO, SrS,
SrSe, SrTe, BaO, BaS, BaSe, BaTe, ZnO, ZnS, ZnSe, ZnTe, CdO, CdS,
CdSe, CdTe, HgO, HgS, HgSe, HgTe, Al.sub.2O.sub.3, Al.sub.2S.sub.3,
Al.sub.2Se.sub.3, Al.sub.2Te.sub.3, Ga.sub.2O.sub.3,
Ga.sub.2S.sub.3, Ga.sub.2Se.sub.3, Ga.sub.2Te.sub.3,
In.sub.2O.sub.3, In.sub.2S.sub.3, In.sub.2Se.sub.3,
In.sub.2Te.sub.3, SiO.sub.2, GeO.sub.2, SnO.sub.2, SnS, SnSe, SnTe,
PbO, PbO.sub.2, PbS, PbSe, PbTe, AlN, AlP, AlAs, AlSb, GaN, GaP,
GaAs, GaSb, InN, InP, InAs and InSb.
[0017] FIG. 2 is a schematic cross-sectional side view of an
illustrative solar cell 20 that is similar to solar cell 10 (FIG.
1). In some cases, a reflective and/or protecting layer 22 may be
disposed over the hole conductor layer 18, as shown. The reflective
and/or protecting layer 22 may be a conductive layer. In some
instances, the reflective and/or protecting layer 22 may include a
Pt/Au/C film as both catalyst and conductor, but this is not
required. Alternatively, or in addition, a flexible and transparent
substrate 24, shown at the lower side (in the illustrated
orientation) of FIG. 2, may be secured to the electron conductor
layer 16. Alternatively, the flexible and transparent substrate 24,
when provided, may be or function as the electron conductor layer
16, and in some cases, may be an n-type electron conductor that is
transparent or at least substantially transparent to at least some
wavelengths of light within the visible portion of the
electromagnetic spectrum.
[0018] As described with respect to FIG. 1, solar cell 10 may
include a bifunctional ligand layer 14. In some cases, bifunctional
ligand layer 14 may include a single bifunctional ligand or a large
number of bifunctional ligands. A bifunctional ligand may, in some
cases, be considered as improving electron transfer by reducing the
energy barriers for electron transfer. A bifunctional ligand may
provide a conduit so that electrons that are ejected by the quantum
dot can travel to and through the electron conductor 16. A
bifunctional ligand may, for example, secure the quantum dots
relative to the electron conductor 16 and/or any other related
structure.
[0019] The bifunctional ligand may include electron conductor
anchor for bonding to the electron conductor 16 and a quantum dot
anchor for bonding to the quantum dots. In some instances, the
electron conductor anchor may include a carboxylic acid moiety, an
amide moiety, an ether or an acid halide. In some instances, the
quantum dot anchor may be selected to bond well to a particular
quantum dot. To illustrate, Ag.sub.2S, CdSe, CdTe and CdS are
examples of quantum dots that may be employed in the light
sensitive assemblies discussed herein.
[0020] In some instances, the bifunctional ligand may include an
antibiotic, and in some cases, a cephalosporin-based ligand. In
some instances, these ligands may be considered as including a
carboxyl group that will bond or otherwise link to an electron
conductor such as titanium dioxide, as well as a sulfur atom that
will bond or otherwise link to quantum dots. A variety of
cephalorsporine-based ligands are suitable. An illustrative but
non-limiting example of a suitable bifunctional ligand is
7-aminocephalorosporanic acid, which has the structure:
##STR00001##
[0021] A number of suitable bifunctional ligands share the
following core structure:
##STR00002##
[0022] where R.sub.1 and R.sub.2 are defined below.
[0023] Another example bifunctional ligand may include cefditoren,
in which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00003##
[0024] Another example bifunctional ligand may include ceftazidime,
in which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00004##
[0025] Another example bifunctional ligand may include cefonicid,
in which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00005##
[0026] Another example bifunctional ligand may include ceftezol, in
which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00006##
[0027] Another example bifunctional ligand may include cefaclor, in
which R.sub.1 is a chloride ion and R.sub.2 is as shown:
##STR00007##
[0028] Another example bifunctional ligand may include cephalothin,
in which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00008##
[0029] Another example bifunctional ligand may include cephradine,
in which R.sub.1 is a methyl group and R.sub.2 is as shown:
##STR00009##
[0030] Another example bifunctional ligand may include
cephaloridine, in which R.sub.1 and R.sub.2 are as shown,
respectively:
##STR00010##
[0031] Another example bifunctional ligand may include cefuroxime,
in which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00011##
[0032] Another example bifunctional ligand may include cefatrizine,
in which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00012##
[0033] Another example bifunctional ligand may include cefamandole,
in which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00013##
[0034] Another example bifunctional ligand may include cefadroxile,
in which R.sub.1 is a methyl group and R.sub.2 is as shown:
##STR00014##
[0035] Another example bifunctional ligand may include cefdinin, in
which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00015##
[0036] Another example bifunctional ligand may include holospor, in
which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00016##
[0037] Another example bifunctional ligand may include
cephalorsporine C, in which R.sub.1 and R.sub.2 are as shown,
respectively:
##STR00017##
[0038] Another example bifunctional ligand may include cefcapene,
in which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00018##
[0039] Another example bifunctional ligand may include cephapirin,
in which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00019##
[0040] Another example bifunctional ligand may include
cephacetrile, in which R.sub.1 and R.sub.2 are as shown,
respectively:
##STR00020##
[0041] Another example bifunctional ligand may include cephalexin,
in which R.sub.1 is a methyl group and R.sub.2 is as shown:
##STR00021##
[0042] Another example bifunctional ligand may include cefpiramide,
in which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00022##
[0043] Another example bifunctional ligand may include
cephaloglycin, in which R.sub.1 and R.sub.2 are as shown,
respectively:
##STR00023##
[0044] Another example bifunctional ligand may include ceforamide,
in which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00024##
[0045] Another example bifunctional ligand may include cefprozil,
in which R.sub.1 and R.sub.2 are as shown, respectively:
##STR00025##
[0046] It will be recognized that at least some of the bifunctional
ligands described herein include carbon-carbon double bonds and
thus some of the molecules may be considered as being either Z
(same side) isomers or E (opposite side) isomers. In some cases, a
solar cell including a number of bifunctional ligands may include
only stereospecific bifunctional ligands, i.e., all Z isomers or
all E isomers, for example. In other instances, a solar cell
including a number of bifunctional ligands may include one or more
Z isomers and one or more E isomers.
[0047] In some cases, a light sensitive assembly or a solar cell
may include one or a number of bifunctional ligands. In some
instances, a solar cell may include a number of bifunctional
ligands that are isomers having the same molecular formula. These
isomers may, for example, be dextrorotatory molecules, levorotatory
molecules or a racemic mixture thereof. In some cases, a light
sensitive assembly or solar cell may include a large number of
bifunctional ligands representing a plurality of chemically
different bifunctional ligands. Each group or subset of
bifunctional ligands, either separately or in combination, may be
dextrorotatory, levorotatory or a racemic mixture thereof
[0048] Referring back to FIG. 1, the illustrative solar cell 10 may
include electron conductor layer 16, which may be formed of any
suitable material or material combination. In some cases, the
electron conductor layer 16 may be an n-type electron conductor.
The electron conductor layer 16 may be metallic, such as TiO.sub.2
or ZnO. In some cases, electron conductor layer 16 may be an
electrically conducting polymer, such as a polymer that has been
doped to be electrically conducting or to improve its electrical
conductivity.
[0049] As discussed with respect to FIG. 1, the illustrative solar
cell 10 may include hole conductor layer 18 that is configured to
reduce a quantum dot once the quantum dot has absorbed a photon and
ejected an electron through the bifunctional ligand to the electron
conductor. While not required, in some instances, the hole
conductor may be a conductive polymer. In some cases, the
conductive polymer may include a monomer that has an alkyl chain
that terminates in a second quantum dot anchor. The conductive
polymer may, for example, be or otherwise include a polythiophene
that is functionalized with a moiety that bonds to quantum dots. In
some cases, the polythiophene may be functionalized with a thio or
thioether moiety.
[0050] An illustrative but non-limiting example of a suitable
conductive polymer has
##STR00026##
[0051] as a repeating unit, where R is absent or alkyl and m is an
integer ranging from about 6 to about 12.
[0052] Another illustrative but non-limiting example of a suitable
conductive polymer has
##STR00027##
[0053] as a repeating unit, where R is absent or alkyl.
[0054] Another illustrative but non-limiting example of a suitable
conductive polymer has
##STR00028##
[0055] as a repeating unit, where R is absent or alkyl.
[0056] Another illustrative but non-limiting example of a suitable
conductive polymer has
##STR00029##
[0057] as a repeating unit, where R is absent or alkyl.
[0058] A solar cell may, for example, be assembled by growing
nanoparticles of n-type semiconducting titanium dioxide on a glass
substrate, optionally followed by a sintering process. Next, the
quantum dots, the bifunctional ligands and the conducting polymer
may be synthesized. Finally, the solar cell may be assembled by
combining the individual components in a one-pot synthesis.
[0059] The disclosure should not be considered limited to the
particular examples described herein, but rather should be
understood to cover all aspects of the invention as set out in the
attached claims. Various modifications, equivalent processes, as
well as numerous structures to which the invention can be
applicable will be readily apparent to those of skill in the art
upon review of the instant specification.
* * * * *